This revised application is for support of four training positions in an established program in digestive diseases at the University of California, San Francisco. Its focus is mucosal biology and clinical research in luminal gastroenterology and pancreas;training in hepatology is a separate program. The mentor group comprises 9 members of the UCSF Division of Gastroenterology and 8 investigators from affiliated Departments and programs who are actively involved in collaborative research with faculty of the Gl Division. All have independent research programs and a record of successful mentoring. The training environment is broadly interdisciplinary, reflecting the involvement of Gl Division faculty in the graduate program for Biomedical Sciences, the Immunology Program, and the Cancer Center. Changes to the Program since the 1999 competing renewal application include: (1) Creation of a comprehensive program in inflammatory bowel diseases, the UCSF Center for Colitis and Crohn's Disease, which encompasses fundamental, translational and clinical research as well as state-of-the-art clinical care;(2) implementation of a program in cancer of the pancreas and another for cancer risk assessment, focused mainly on colon cancer;and (3) a K30 award to the UCSF Department of Epidemiology and Biostatistics, to expand its didactic program in clinical research methods with a Master's degree in Clinical Research. In the year since the initial submission of this renewal proposal, a program in outcomes and health services research has been formally constituted under the direction of John Inadomi, MD. Also, the School of Medicine received an institutional K12 award for training of both fellows and junior faculty in translational research. Subspecialty fellows selected for support under this training grant generally will hold an MD or MD/PhD and will have completed both a program in Internal Medicine and 12 months of intensive training in clinical gastroenterology. Highly qualified PhD recipients, whose research is focused on the Gl tract and has translational potential, also may apply. The duration of research training is three years, except for fellows with exceptionally strong prior experience who may do two years only. Program graduates will have a well-defined research focus and the tools needed for success with a career in biomedical investigation in the field of gastroenterology.